I'm a pretty big board gamer with a collection somewhere north of 300 games and I feel by and large the influencer community isn't as bad as in other niches. Most people will state very clearly if they got a review copy or have other relations (sometimes they'll review a game from a publisher were they are also publishing a game soon etc.).

Mostly, the good creators are still people who like board games and there's not so many that have more of the "pro influencer" vibe. Not surprisingly, there was a pretty big shitstorm around one of the channels that always seemd super influenc-y recently (don't want to explicitly name it but the channel name related to the typing in Python).

However, I'd argue that board gamers tend to be overly enthusiastic in reviews in general and focus mostly on the positive. We (I'm not a content creator just a player of games) want to like games as a default :D I'd also say that written text is still quite valuable in board gaming circles with boardgamegeek as the obvious example. At least I tend to research there and get my first contact with new games from Geeklists and the likes rather than from videos.

Apart from review videos, another kind of video is rules explaination (or playthrough) type of videos. These are somtimes payed for because (frankly speaking) the publishers couldn't do it themselves at these price points. To me this is a perfectly fine source of income for youtubers. Some content creators also do this for free anyways but typically these videos are very neutral just focusing on the rules. From a customer's point of view they tend to be quite good to get an impression of the games without any review content.